Measurement of 7Li(n, gamma 0)8Li cross sections at En=1.5-1340 eV.

Abstract

The {sup 7}Li({ital n},{gamma}){sup 8}Li cross section is important in inhomogeneous big bang models, and as a constraint on model parameters used to determine the solar {sup 7}Be({ital p},{gamma}){sup 8}B reaction rate. Values of the {sup 7}Li({ital n},{gamma}{sub 0}){sup 8}Li reaction cross section were measured for neutron energies between 1.5 and 1340 eV at the Oak Ridge Electron Linear Accelerator. The normalization of the cross section was determined by measuring the gamma-ray yield from the {sup 7}Li({ital n},{gamma}{sub 0}){sup 8}Li reaction relative to that from the {sup 10}B({ital n},{alpha}{gamma}){sup 7}Li reaction. The cross section was found to have the inverse neutron-velocity relationship (1/{ital v}) indicative of {ital s}-wave capture. These results help resolve ambiguities in previous measurements. {copyright} {ital 1996 The American Physical Society.}